The mass number for an isotope is 211. The number of neutrons is 1.51 times higher than number of protons. Show your work and solve for number of protons and identify the element.

84 protons

Explanation:

atomic mass = # of protons + # of neutrons ( number of P is unknown )

      211        =     P + 1.15 P

      211         =    2.15 P  ( solving a linear equation )

           so we find that the number of protons = 84

its the polonium isotope

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.